FWIW, I test drove a Lexus IS with electronic power steering this past weekend and was impressed with how well it performed. I'm not sure of its durability, then again, Lexus has always been near that top of the heap in that category. :P

 

Electric power steering is a boosting system, similar to hydraulic power steering. The wheel is still mechanically connected to the steering linkage, it's just getting some assistance from an electric motor (instead of a hydraulic pump). If the EPS died, you can still steer, although you better be fairly strong.

I know that pure hydraulic steering, where there is no mechanical link, is not road legal. I suspect the same would be for purely electric steering.

Are you sure about that? I'm not aware of any electronic throttle system that has a mechanical (I assume you mean cable) backup. The gas pedal is connected to a sensor, that's it. Electronic throttle system often have a limp home mode, but that's different than having a backup.

 

All I know is on the two cars of mine that I've bothered to check there's two cables to the throttle body/valve... one appears to be connected to the electronic throttle control and has a free range of movement when the car is on but doesn't move at all when the car is off. The second one moves no matter what, but it has a very limited range... like I could floor the car while it's off and the cable might open the valve by 25% at the most. Maybe that's the "limp home mode" but it's still a backup for safety purposes.

 

GM cars with electronic throttle do not have cable backups. I'd be surprised to learn of any that do.

Also, R377 already posted basically what I was going to say about electric power steering. It is electric ASSIST people, just like hydraulic ASSIST. My John Deere 345 has "power steering" that is purely hydraulic (i.e. a hydraulic cylinder, moving fore and aft, just like one you'd see powering the arm of a backhoe). You would not want that for a car.

But electric assist and hydraulic assist both still have steering shafts going into the steering rack; they just differ in how the assist is provided. In both cases, if the system fails, you can still steer. The steering just gets heavier.

Honestly, cars have had EPS for YEARS now. I'm surprised that the misconceptions are still out there that somehow the car is "steer by wire" like an electronic throttle control (which has shown up in concepts and such, but not in production as far as I know).

 

My HHR had it. It has an artificial feel overall. Hard to describe, but there is a disconnected feel that doesn't lend well to handling.

 

If there were cables going to the throttle body, that sounds like a cable actuated throttle. I'm obviously most familiar with GM's DBW, but the throttle is controlled by a motor located right on the TB. See - http://www.c5racer.com/catalog/images/2099.jpg

I know you've had audi's and bmws, a quick google search shows images of either old style TB, or what looks like a locally mounted drive motor TB like the LS2.

http://images.google.com/images?gbv=...+throttle+body

http://images.google.com/images?gbv=...+throttle+body

 

Yeah, probably a crock of $h!t invented by the guy who wrecked the car. The S-197 has had e-throttle since its debut (with no mechincial backup) and no real failures that I know of. The biggest complaint is laggy throttle response (supposedly doing a sequence of events - can't remeber the exact process - will eliminate the lag).